Apparatus for straining fluids



25 1927" F. BAILEY ET AL APPARATUS FOR STRAINING FLUIDS Original Filed July 1, 1925 4 Sheets-Sheet 1 w l wiiwr imi l L%m E /N VE N TORS.

Jan. 25, 1927.

I F. BAILEY ET AL APPARATUS FOR STRAINING FLUIDS Original Filed Jul 1 4 Shets-Sheet 2 Jan. 25,

- F. BAILEY ET AL APPARATUS FOR STRAINING FLUIDS.

Original Filed July 1 1925 4 Sheets-Sheet Jan. 25,1927.

F. BAILEY E L APPARATUS FOR S TRAINING FLUIDS Originai Filed July 1, 1925 4 Sheets-Sheet [N VEN TORS.

E f M Patented Jam 25, 1927.

.UNITED STATES PATENT OFFICE.

FRANK BAILEY AND FREDERICK HENRY JACKSON, OF SOUTHWARK, ENGLAND.

APPARATUS FOR STRAINING FLUIDS.

Original application filed July 1, 1925, Serial No. 40,915, and in Great Britain October 24, 1924. Divide-d and this application filed January 8, 1926. Serial No. 80,083.

In the specification to the British patent, granted to us and dated 10th February 1903, No. 3,149, is described a self-cleansing strainer comprising a drum-shaped casing, traversed axially by a horizontal shaft, whereon is mounted a wheel, furnished, be tween its spokes, with grids which serve as straining media; and in the specification to our British patent, dated 12th September 1918, No. 131,755, is described a self-cleansing strainer of a similar character wherein, instead of only half the straining surface being effective for straining purposes, a larger proportion thereof is rendered available for that purpose, whilst the cleansing operation is effected through a comparatively small portion thereof.

a Our present invention consists in certain improved methods of construction with the same object, and whereby a still larger proportion of the straining surface is rendered available for straining purposes. Inasmuch, moreover, as the strainer-wheel,.instead of rotating, is a fixture, the friction, wear and leakage, which have hitherto occurred between the periphery of the straining wheel and its casing are avoided.

This case is a division of application 40,915, which matured into Patent Number 1,585,817, of May 25, 1926, and in which is described a construction. of strainer similar to that herein referred to but designed for use where the apparatus is arranged on the delivery side of a pump and is therefore working under pressure. It is however frequently deemed preferable to place a strainer on the suction side of the pump, and consequently to work under a partial vacuum; the debris being removed from the water prior to its passage through the pump, The method of construction hereinafter descrlbed is more particularly intended for working under these latter conditions.

straining apparatus constructed according to our invention and adapted for working under partial-vacuum 1s lllustrated 1n the accompanying drawings, whereof Fig. l is a longitudinal vertical section, Fig. 2 a transverse vertical section and Fig. 3 a transverse horizontal section.

Fig. 4 illustrates in side elevation and Figs. 5 and 6 in vertical section, valve appa ratus for controlling the discharge of the flushing water.

Fig. 7 shows in face view, Fig. 8 in edge view and Fig. 9 in transverse section, ratchet working positions.

Assuming the strainer to be arranged on the suction side of apump and therefore to work under a partial vacuum, the apparatus comprises a cylindrical chamber wherein is fixed a circular straining diaphragm, preferably formed as a disc a with radial spokes a the spaces between the spokes constituting sector-shaped chambers the backs of which are formed of grids a the fronts of the said chambers being open. On the inlet Z), or unstrained-water side of the strainerdisc, is mounted a box-like chamber 0 corresponding in form substantially with that of one of the sector-shaped grids; the face of the box presented to the strainer-disc being open. For balancing purposes, we prefer to employ two such box-like chambers herein referred to as cleanser-boxesand arrange them to extend radially from opposite sides of the centre. 3 A single cleanserbox may however be employed, and a counter-balance weight substituted for the cleanser-box on the radially opposite side. On the opposite side of the grid a and opposite the cleanser-box c is arranged a similar box 0 hereinafter referred to, forthe purpose of distinction, as a flushing box. This supplementary box is mounted fast on the shaft f whichis free to slide longitudi nally in its hearings to a limited extent. The

cleanser-box c is mounted fast upon the hollow-shaft or sleeve f, which latter is also capable of a limited longitudinal movement; the two boxes 0 0 together constituting a fiushing-chamber. Both the shaft 7 and the sleeve 7 extend through the casing and are suitably packed to prevent the ingress of air. Upon the outer ends of the shaft f and sleeve 7 respectively-are fixed discs 9 g of the ratchet type for effecting the intermittent rotation of the cleanserand flushing-boxes 0 c by means of a claw-pawl k of such form that the oblique pressure exerted in driving tends to draw the discs together,

and thereby torelieve the pressure of the boxes 0 0 upon the faces of the straining disc.

The requisite suppl of cleansing water may be taken from t at delivered by the pum or from any other convenient source. In igs. 2 and 3 is shown provision for its introduction by way of a assage 12 between two of the straining grids, and for its escape, together with the debris, by way of a like passage 72 arranged, in the present instance, on the radially opposite side of the straining disc. 1

Delivery from the passage 12 is controlled by means of a valve such as described with reference to Figs. 4, 5 and 6; but when working on the suction system, theinlet passage p 1s also-subjected to control by a me chanically operated shutter or valve 9 (Fig. 2), the action of which is suitably timed to suit the movements of thecleanser and flushing boxes 0 a. Y x

A valve suitable for controlling the discharge from the flushing chamber is illustrated in Figs. 4, 5 and 6. The valve is of V-section, has a shut-01f flap Z and a pressure balancing fla Z; the pressure-water gaining access to t 6 back of the latter flap by way of the passage 1 with a straining grid. The valveis mounted upon a spindle l which passes through glands, arranged in the sides of the valve-casing, and is provided at one end with an arm Z and at the other end with an arm Z which latter is furnished with an adjustable weight for balancing purposes. In order to ensure a quick and wide opening for the discharge tremityof a lever l' pivoted, at Z. In the position shown in Fig. 4, the tension of the sprin tends to hold the flap Z of the valve close upon its seating; but upon the. lever Z being, vibrated, the line along which the sprin exerts its tensional effort is trans ferre .to the'opposite side of the axis of thevalve-spindle l with theefiect that thevalve- Suddenly opensl. -In. like "manner, upon the lever I being moved-in the opposite direce tion belyond' its central position, the valve sudden y closes. v The operation of'this valve -is timed to open and. close whilst the cleanser-box is seated and remains stationar against one of the strainer-chambers, an 'thevalveremains'clo'sed' during the movement of the cleanser-box to a position opposite the strainer-chamber next in rotat on.

The ratchet and pawl-mechanism herein before referred to for operatingthe cleanser-- aoiaeoe reciprocating rod connected between the radial extensions 7' 9' The working faces of the teeth of the ratchet-wheels g g are inclined in opposite directions, as shown in Figs. 7 and 8; and the working face of the pawl is formed to correspond, the effect of which is to draw the ratchet-wheels towards one another, and thereby to reduce or eliminate the' friction between the faces of the boxes 0 c and the faces of the disc whichcarries the strainin grids a, during the ro-, tative movement-0% the former in relation to the latter; both the shaft f and the sleeve 7 being capable of sliding to a limited extent in their bearings. Upon the pulling eifort of the pawl upon the teeth of the ratchet-wheels ceasing, spiral springs which are housed in recesses in the adjacent faces of the ratchet-wheels, as shown on a larger scale in Fig. 9, come into operation to force the. ratchet-wheel's apart and to seat the boxes 0 0 water-tight against the opposite faces of the strainer-disc. In order to pro vide against the ingress of air between the ratchet-wheels and along the shaft 7 a U shaped leather or other suitable inserted between the wheels 9 9.

For the purpose of correctly registering the positions of the cleanser and flushing boxes 0 .0 in relation to the respective strainer-grids a whilst being'flushed, one or more roller-furnished and'spri'ng-supported plungers 0 are mounted in thegmapacking nis chine-frame; the rollers o engaging in shallow recesses 0 formed in suitable positions in the'inner'surface of the rim of the ratchet devices serve. to preven inconvenient oscillation or mowheel g, Such semi-locki tion of the boxes during. the debris-flushing periods. The comparatively slight locking efi'ect of the plungers' 0 is readily overcome upon the pawl It? coming into-operation.

For the better seating of the cleanser and flushing-boxes durin their cleansin periods, they may be riven slightly. yond their true seating positions, and then returned to their correct positions, either by the locking device of the awl.' a In ig. 10 -;is,illust'rated the manner in which certain parts hereinbefore described in detail are or may be assembled. The reor by] the return-stroke volvi'ng crank 1' vibrates two levers Z and g; the former operating a partially balanced valve of the character described with reference to Figs. ,4, 5 and 6, whilst the lever q controls the admission of the water used for flushing. The crank 1" also vibrates the lever jwhich operates the ratchet and pawl mechanism, described with reference to Figs. 7, 8 and 9, for gradually rotating the cleanserbox 0 and the flushing-box 0 As already stated, the flushing and cleanser boxes rotate in unison; and whilst they are in movement, the inlet valve g and the outlet valve Z are closed. Upon the said boxes having arrived opposite one of thegrids a these valves are opened to admit the flushing water by way of the passage 1), and to permit of its exit by way of the passage 70 the water traversing in its course the particular grid a enclosed between the two boxes. The valves 9 and Z are then closed, and the flushing and cleanser boxes proceed to the next straining grid in succession. Means whereby the relative movements of mechanical appliances, such as the valves referred to, may be suitably timed are wellknown.

The apparatus herein described and claimed is primarily intended for use in straining water and for the purpose of description, we have confinedourselves thereto; but we would have it understood that the general principle. of construction is equally applicable in the removal of solid impurities from other liquids or aeriform fluids.

We claim 1. A self-cleansing strainer comprising a chamber, a circular straining medium which is stationary and is divided into numerous sectors fitted with straining grids, a sectorshaped cleanser-box and a like flushing-box arranged on the opposite sides of the said straining medium, and means for gradually rotating them in unison; the said boxes constituting a chamber which encloses the ridfurnished sector whilst undergoing theushing operation.

2. For use in a self-cleansing strainer of the character defined in claim 1, afartially balanced valve for controlllng the ischar of the water employed for flushing t e connection with a rod whereby the valve is operated; the arrangement of the parts be ing such that the spring fully opens or fully closes the valve upon the operatlng lever entering upon the second half of its stroke.

3. For use in operating a pair of cleanser and flushing-boxes such as referred to in claim 1, duplex ratchet and pawl mechanism comprisin two ratchet-wheels, respectively in connection with the two boxes, and a clawpawl in operative relation to both ratchet wheels; the ratchet-teeth of the respective wheels being inclined in such a manner that, when subjected to the ull of the clawawl, the two discs are slight y drawn towar one another against the eifort of springs acting in the opposite direction, with the efiect that the pressure of the cleanser and flushingboxes upon the opposite faces of the strainerdisc is relieved and the rotation of the boxes facilitated.

4'. For use in conjunction with duplex ratchet and pawl mechanism ofv the character herein described and with a cleanser-box, a semi-locking device consisting of a rollerfurnished and spring-supported plunger mounted in the strainer-disc, in con unction with a ratchet-wheel having, in the inner face of its rim, a recess ada ted for the reception of the plun er-carriedroller; such device serving to c eck oscillation of the cleanser-box during the flushing operation.-

5. In a self-cleansing strainer of the character defined in claim 1, the combination, with a mechanically 0 rated valve for controlling the escape of t e water used in flushing the strainin grids, of a mechanically operated valve or controlling the inlet of the flushin water, and means for suitably timing their operations in relation to the movement of the flushing and cleanser boxes.

FRANK BAILEY. FREDERICK HENRY JACKSQN. 

